#include <iostream>
#include <vector>
#include <algorithm>
#include <set>

using namespace std;

static bool prime(uint64_t num) {
    if (num < 2) return false;
    if (num == 2) return true;
    if (num % 2 == 0) return false;

    for (uint64_t i = 3; i * i <= num; i += 2) {
        if (num % i == 0) return false;
    }

    return true;
}

int main() {
    constexpr uint64_t lim = static_cast<uint64_t>(1e8);
    vector<uint64_t> p {2};
    for (unsigned i = 3; i <= lim / 2; i += 2) {
        if (prime(i))
            p.push_back(i);
    }

#if 1
    set<uint64_t> s;    
    for (auto i = 0; i < p.size(); ++i) {
        for (auto j = i; j < p.size(); ++j) {
            uint64_t t = p[i] * p[j];
            if (t <= lim)
                s.insert(t);
            else 
                break;
        }
    }
    cout << s.size() << endl;
#endif 
}   // 17427258